Hi guys......
somehting rather odd happened to me many years ago when I was at school in chemistry class. - I remembered (from an earlier year) about an experiement involving a white coloured gas and sulphur that smelled like rotten eggs.....
......so naturally when we were burning sulphur (and produced a white gas, which i think was sulphur dioxide, I had a good old sniff) - This resulted in my sinuses closing VIOLENTLY. - It was an involuntary reaction...... any idea what caused this ?